Down Syndrome, mastication, tongue habits, low birth weight, eating, children


Down syndrome (DS) has the highest prevalence of any chromosomal abnormality identified in newborns. DS children have specific eating and swallowing difficulties such as poor tongue control, mouth opening, swallowing food without chewing, and both facial and occlusal abnormalities. DS children are also at high risk of aspiration, and swallowing food without chewing is considered to be a factor associated with increased risk of aspiration and eating problems. This study aimed to identify factors preventing the acquisition of masticatory function in DS children. The subjects were 75 outpatient DS children (44 males, age range 12 to 36 month-old, mean age 33.0 ± 7.0 month-old; 31 females, age 12 to 36 month-old, mean age 20.8 ± 8.0 month-old), who had not yet acquired masticatory function, out of 319 who visited the clinic between October 2012 and October 2017. The information necessary for assessment was retrospectively extracted from the medical records of the subjects. The items examined included age, birth weight, nutritional intake, picky eating, tactile hyperesthesia, cognitive development assessed by Ohta stage, gross motor function, occlusal condition by Hellman’s dental age, and tongue thrust/lip closure/mastication while eating. The relationships between the acquisition of masticatory function and these items were investigated after one year of rehabilitation. The revealed age, low birth weight, picky eating, and gross motor function to be relevant factors. Among these, gross motor function was found to be the factor most strongly associated with acquisition of masticatory function.